#include <iostream>
#include <string>
using namespace std;

int main() {
  string str1 = "abcdefgh";
  str1.insert(0, "1");
  cout << "str1 = " << str1 << endl;

  str1.insert(1,2, '2');
  cout << "str1 = " << str1 << endl;

  str1.erase(0,3);
  cout << "str1 = " << str1 << endl;

  return 0;
}